"All this region is very level and full of forests, vines and butternut trees. No Christian has ever visited this land and we had all the misery of the world trying to paddle the river upstream." Samuel de Champlain

With many parts of the world suffering from scarce freshwater, recycled household water represents a prodigious potential resource. Some researchers envision neighborhood treatment systems to someday reuse homes' so-called "gray water," the wastewater from sinks and baths. Dutch scientists have now tested these methods and find that despite some success in removing pollutants derived from personal care products, further improvements are needed.

Although homes have just one sewer line, conservationists see two distinct kinds of water flowing into it: Toilets generate so-called "black water," whereas sinks, washing machines, and showers produce gray water. Because this gray water constitutes about 75% of household water usage, experts think it's a promising target for local reclamation.

Although gray water has a lighter pollutant load than wastewater from toilets, it still contains chemicals found in personal care products, such as the antibacterial agent triclosan and the preservative propylparaben. Researchers have been developing systems to someday treat gray water within neighborhoods, or perhaps even in individual homes, so it can be reused to flush toilets or irrigate lawns and gardens.

In the laboratory, (Dutch environmental scientist)Hernández Leal and colleagues subjected gray water samples to the typical biological treatments used in sewage facilities: They added sewage sludge to the water, and the sludge's microbes chewed up organic chemical contaminants for 12 hours.

The researchers then analyzed the treated water for 18 compounds from personal care products using gas chromatography/mass spectrometry. The sludge treatments removed about 80% of most of the contaminants, but the treated water still contained organic pollutants at low microgram-per-liter levels, which are problematic. For example, at 3.8 µg/L, the sunblock ingredient ethylhexyl methoxycinnamate contributes to the treated water's overall potential as an estrogenic disruptor."

I'm the second generation of my family that lives in Richelieu, Quebec, in Canada. My family tree, both from my mother's and my father's side, has its roots in Quebec since the beginning of the 1600s: my ancestors crossed the ocean from France, leaving Perche and Normandy behind them. Both French AND English are my mother tongues: I learned to talk in both languages when I was a baby, and both my parents were perfectly bilingual too.